The present invention relates to solutions for containment or management of fecal output. Options for containment or management of fecal output known in the art include absorbent pads in the form of diapers or sanitary napkins, anal plugs, fecal collectors in the form of collection bags or pouches, and indwelling catheters.
Of the various available solutions, indwelling catheters provide a promising solution for managing fecal incontinence. An indwelling catheter is placed inside the rectum and a retaining member comprising a resilient ring or an inflatable balloon or cuff is used to hold the catheter inside the rectum. The retaining member is delivered in a compressed state into the rectum through the anal opening, and is allowed to, or caused to expand within the rectum. In its expanded state, the retaining member abuts against the shelf provided by the anorectal junction (which provides a shelf at the junction between the broader passage of the rectum and the narrower anal canal) and is prevented from being unintentionally withdrawn from the rectum and through the anal opening. The retaining member also provides an annular lumen to allow passage of stool. The retaining member is connected to a collection bag, for feces.
Existing indwelling catheters have several shortcomings.
A primary drawback of prior art devices is that the retaining member is configured to assume and retain its expanded state within the rectum, causing the resilient ring or inflatable structure to apply a continuous externally directed radial force against the walls of the rectum, causing rectal tissue aggravation, mucosal damage, rectal stenosis, degeneration of the internal or external nerves and rupture of the superior rectal blood vessels.
Additionally, in the natural state, fecal matter is expelled from the colon and rectum by a wave like muscular contraction of the colon and rectal walls (peristalsis) and a corresponding relaxation of the sphincter. Peristaltic contractions cause the rectal walls to expand and contract to move fecal matter towards the anal opening. In cases where a prior art indwelling catheter has been inserted into the rectum, externally directed radial forces exerted by the retaining member interferes with peristaltic contractions at the point at which said member has been disposed within the rectum. The continual pressure exerted by the resilient member also causes damage to the rectal walls and to the internal or external sphincter leading to permanent dysfunction.
In certain cases, the resistance presented by the resilient member to the rectal walls during peristaltic contractions causes said resilient member itself to be expelled towards the anal opening, until it is forced to abut against the anorectal junction, or in some cases is expelled entirely from the anal canal.
Prior art devices additionally fail to taken into account physiology of the rectum and anal canal. The anorectal junction (the common boundary of the rectum and anal canal) provides a limiting boundary for particular nerve types. Visceral nerves are found above the anorectal junction, while somatic nerves are found below said junction. Somatic nerves are capable of sensing pain, while visceral nerves only sense pressure and not pain. By virtue of the somatic nerves, the anorectal junction and portions below it are extremely sensitive, and cause a high level of discomfort in case of foreign objects located within the anal canal.
A large number of prior art devices rely on a retaining member located at and abutting against the shelf provided by the anorectal junction. In other prior art devices, as a consequence of resistance of the retaining member to peristaltic contractions, said devices are moved as a consequence of the peristaltic contractions toward the anal opening, until they rest against the shelf provided by the anorectal junction. As a result of the retaining member residing at the anorectal junction, the patient is constantly aware of a foreign body sensation with resulting discomfort. For this reason, prior art devices have not been particularly successful for patients, other than those in intensive care.
In terms of effectiveness, prior art devices have so far only been successful with respect to non-solid fecal matter. Limitations to effectiveness have multiple causes. First, the anal canal and anorectal junction provide passages with a limited lumen diameter for passage of fecal matter. Situating a retaining member comprising either a continuous ring (or cylinder) of resilient material, or an inflated cuff or balloon, within the rectum further reduces the lumen diameter to a significant extent, which reduces the available volume for passage of fecal matter. The reduction in available lumen diameter precludes the passage of any significant quantity of solid fecal waste.
Another constraint faced by prior art devices is the likelihood of being dislodged. Regardless of whether the retaining member comprises a resilient ring or an inflatable cuff, the upper rim of such resilient ring or cuff (the rim which is furthest from the anal opening) presents an abutment surface against which descending fecal waste would necessarily impact. Pressure exerted by descending solid fecal waste against the abutment surface causes the retaining member to be dislodged, so that it no longer presents the complete annular lumen for passage of stool, consequently causing leakage or seepage along outside walls of the resilient member. Moreover, once dislodged, the resilient member presents an increased abutment surface area, against which pressure continues to be exerted by solid fecal waste, eventually leading to the entire device being expelled from the anal opening.
Owing to the limitations in addressing solid fecal discharge, usefulness of prior art devices is limited to addressing liquid fecal discharge, which is typically observed only in patients in intensive care.
Prior art devices also face a serious drawback in terms of leakage/seepage caused by peristaltic contractions. FIGS. 16 to 17A illustrate cross sectional plan views of the retaining member of prior art devices and the consequences of peristaltic contractions by the rectal walls. The teachings of said figures are equally applicable to cases where the retaining member is a resilient ring, and where the retaining member is an inflatable cuff. In both cases, the retaining member presents a solid, continuous annular surface that resides against the rectal walls.
In FIG. 16 a retaining member 10 of the kind observed in prior art devices is in its fully expanded state, and assumes a uniformly circular (or substantially circular) shape. FIG. 16A demonstrates the effect of inwardly directed radial forces F along certain points on the circumference of said retaining member 10, in that portions of the resilient member on which inward forces F are directed, deform inwards, while other portions are correspondingly deformed outwards. Corresponding outward deformation of portions of retaining member 10 is a consequence of the solid and continuous annular structure of said retaining member 10. Where retaining member 10 is a resilient ring, the outward deformation is a consequence of the resilient properties of the constituting material. Where the retaining member 10 is an inflated cuff or balloon, the outward deformation is a consequence of relative incompressibility of air within the cuff or balloon, which applies corresponding pressure on other portions of the resilient member.
FIG. 17 illustrates retaining member 10 in its fully expanded state when disposed within the rectum. Adjacent rectal walls 94 are illustrated in a relaxed state, wherein no inwardly directed forces are applied on retaining member 10. In FIG. 17A the rectal walls 94 are illustrated undergoing a peristaltic contraction, wherein inwardly directed radial forces F are applied at various points on the circumference of retaining member 10. Since the inwardly directed compressive forces F are applied across the circumference of retaining member 10, said member 10 is forced to collapse inwardly into a series of substantially U-shaped deformations, with a view to reduce the circumferential surface area presented by retaining member 10 adjacent to rectal walls 94. The U-shaped deformations interfere with and reduce available lumen volume for passage of fecal matter through the retaining member. Simultaneously, such U-shaped deformations created gaps between rectal wall 94 and circumference of retaining member 10, through which fecal matter can pass, leading to seepage or leakage along the outside of the device.
In addition to the disadvantages set out above, it has generally been observed that prior art devices require a trained care provider to prescribe, insert, maintain and remove the device.
The applicant has recognized a need for a collection device for fecal discharge that addresses all of the above shortcomings, embodiments whereof are described herein.